1. Field of the Invention
The present general inventive concept relates to a method and apparatus to control an optical disk driver, and more particularly, to a method and apparatus to predict a position at which land/groove switching occurs in a seek mode, and to stably execute a seek servo using the predicted land/groove switch position.
2. Description of the Related Art
Well-known documents related to the present general inventive concept include Korean Patent Laid-open Application No. 2001-76556 and U.S. Pat. No. 6,233,207.
In general, an optical disk has been widely adopted as an information recording medium of an optical pick-up device for recording/reproducing information in a contactless manner. Optical discs are classified into Compact Discs (CDs) and Digital Versatile Discs (DVDs) according to storage capacities thereof. Particularly, DVD-type optical discs that can record and reproduce information include DVD-Random Access Memories (DVD-RAMs) and DVD-rewritables (DVD-RWs).
A great difference between a DVD-RAM and a DVD-RW exists in physical regions on which data is recorded. That is, in a DVD-RAM, information is recorded using all land and groove regions formed in the disc, however, in a DVD-RW, information is recorded on only groove regions formed in the disc.
The DVD-RAM controls a seek speed in a seek mode and executes tracking control in a normal play mode by using a tracking error signal. However, a phase of a tracking error signal in land regions are opposite to a phase of a tracking error signal in groove regions. Accordingly, inverting the phase of a tracking error signal at a land/groove switch position is needed.
In the normal play mode, since a land/groove switch position can be accurately detected using header information recorded in an optical disc, inverting the phase of a tracking error signal using the land/groove switch position is possible.
However, in the seek mode, since head information cannot be accurately read, detecting a land/groove switch position is possible.
Accordingly, when a land/groove switch position is not accurately detected in the seek mode, a seek speed is controlled using a tracking error signal having a wrong phase at any land/groove switch position, which deteriorates performance of controlling the seek speed. Also, when a land/groove switch position is found at a tracking pull-in time, the phase of the tracking error signal becomes opposite to a desired phase to be controlled, so that a track deviation phenomenon occurs and the performance of tracking control deteriorates.